This invention relates to exercise apparatus for toning and building muscles in the human body, and more particularly to a new exercise machine that utilizes the weight of the user as a load factor to provide mechanical impedance for exercise.
In recent years exercise machines have gained a great deal of popularity with the general public. Whereas formerly such machines were used primarily by athletes for enhancing their performance in their chosen sport, exercise devices are now used by a large number of non-athletes for such purposes as conditioning, aerobic activity, and improvement in appearance through muscle-building activity. This growth in use of exercise machines has created an expanding market for home-based units, as well as installations in athletic clubs, fitness centers, resorts, cruise ships, and other recreational and sports facilities.
Several basic concepts are embodied in most exercise machines. The apparatus should be able to exercise as many muscle groups of the body as possible, to provide the most complete workout. In the prior art, some exercise machines are adaptable for total body workout, but reconfiguring the machine involves a level of mechanical ingenuity that many people do not possess. Furthermore, dismantling and reassembling portions of the machine requires some time, and these tasks interrupt the flow of a good physical workout and limit the aerobic quality of the activity. An ideal exercise machine should be adaptable to a total body aerobic workout without delays due to mechanical limitations of the machine itself. The prior art has been deficient in this respect. In health clubs and the like it is possible to provide a group of variously configured machines in a training circuit, each machine dedicated to a particular exercise or muscle group, so that an ongoing aerobic workout may be achieved by using the different machines serially. However, in home installations or the like economic necessity requires that a single machine provide all of the exercise potential of the plurality of machines, without significant interruption for reconfiguration.
Another design consideration for exercise machines is the need to provide a selectively variable mechanical resistance for the various muscle groups and movements required for exercising them. Impedance must be adjustable so that weaker individuals can undertake exercise without straining their muscles, while stronger individuals can select sufficient resistance to their exertions to provide meaningful exercise.
Early designs utilized discrete weights that could be added to a loading assembly that is lifted through cable and pulley arrangements. This system was improved by adding cam devices to vary the weight load during extension and retraction of the limbs during each exercise. Later machines have employed discrete springs or elastic bands to provide resistance to exertion, or fluid damping devices (pistons displacing air or liquid through a restricted orifice), which offers the ability to provide infinite variation in resistance. Mechanical resistance from sliding or rotating surfaces have also been used, although adjustability and reproducibility have been problematic. There is no clearly preferable mechanical impedance arrangement in the prior art. All of them must be readjusted for each new user of the machine; e.g., a 170 lb. person must readjust the weights, elastic bands, or dampers of any machine when the previous user was a 120 lb. individual.
Another important design consideration is the safety of the apparatus. Falling weights, breaking elastic bands, or failing mechanical or fluid dampers can result in uncontrolled movement of the machine. The result can be hyperextension of joints, or impact and injury to the individual using the machine.
To summarize the state of the art in exercise machines, there is a design ideal involving adaptability, adjustability, ease of use, and safety. This ideal has not been met by any one device, and many devices have fallen far short of the ideal.